CN110577648B

CN110577648B - Preparation method of hydrophobic polycaprolactone

Info

Publication number: CN110577648B
Application number: CN201910833772.6A
Authority: CN
Inventors: 李战雄; 李武龙; 王海朋
Original assignee: Suzhou University
Current assignee: Suzhou University
Priority date: 2018-04-19
Filing date: 2018-04-19
Publication date: 2021-09-28
Anticipated expiration: 2038-04-19
Also published as: CN108484922A; CN108484922B; CN110577648A

Abstract

The invention discloses a preparation method of hydrophobic polycaprolactone, which comprises the following steps: reacting polycaprolactone with an amino alcohol compound to prepare hydroxyl-terminated polycaprolactone; reacting hydroxyl-terminated polycaprolactone with anhydride to prepare carboxyl-terminated polycaprolactone; reacting ethylene glycol bromoisobutyrate with fluorine-containing alkyl acrylate to prepare hydroxyl-terminated fluorine-containing polyacrylate; and reacting the carboxyl-terminated polycaprolactone with hydroxyl-terminated fluorine-containing polyacrylate to prepare the hydrophobic polycaprolactone. The product of the invention has controllable molecular weight of the hydrophobic chain segment, narrow molecular weight distribution and controllable fluorine content and hydrophobicity. When the hydrophobic polycaprolactone is prepared, the end group activated fluorine-containing polymer is prepared in advance, a fluorine-containing polymerization product is obtained in a homogeneous system, and the polymerization degree is easy to control. Solves the problem that the solubility is changed and the fluoropolymer chain is difficult to directly generate at the PCL chain end in situ. PCL containing active carboxyl and organic fluorine polymer containing active hydroxyl are directly condensed under mild reaction conditions to prepare a product, thereby avoiding degradation of the PCL.

Description

Preparation method of hydrophobic polycaprolactone

The invention relates to a hydrophobic polycaprolactone and a preparation method thereof, and a divisional application with the application number of 2018103566141 and the application date of 2018, 4 and 19, belonging to the part of a product preparation method.

Technical Field

The invention relates to a high-molecular modification technology, in particular to hydrophobic polycaprolactone and a preparation method thereof.

Background

Polycaprolactone (PCL) is a linear aliphatic polyester obtained by ring-opening polymerization of omega-caprolactone monomer under catalysis of metal organic compound (such as tetraphenyltin), and has excellent biodegradationThe film has good solubility, good biocompatibility, good drug permeability and good mechanical property, is certified by the American FDA, and has wide research and application in the field of film application. The melting point of Polycaprolactone (PCL) is 59-64 ℃, and the glass transition temperature is-60 ℃. Having 5 nonpolar methylene-CH groups in the structural repeat unit₂And a polar ester group-COO-, i.e., - (COOCHCH)₂CH₂CH₂CH₂CH₂-) Pn, such a structure allows good flexibility and processability of the PCL, while the material is biocompatible.

At present, the research on the application of polycaprolactone as a biomaterial is the most extensive, and particularly, there are many reports on the research and application of polycaprolactone as a biomaterial scaffold for human tissue repair and in the biomedical field of slow release of drugs. In these applications, when polycaprolactone is used as a tissue scaffold in contact with body fluids, such as artificial nerves and artificial blood vessels, the inner wall of the tube may adsorb active ingredients in the body fluids when contacting the body fluids, which may cause deposits to adhere to the tube wall and sometimes even cause the tube wall to be clogged. Thus, hydrophobic modification of polycaprolactone has been proposed.

However, polycaprolactone lacks reactive pendant functional groups on the macromolecular chain, making it difficult to provide hydrophobic materials by modification by side chain chemical grafting and the like. Therefore, the active end group of the polycaprolactone is converted into carbon-bromine bond (C-Br), and then the block copolymer is obtained by the radical polymerization of unsaturated monomers such as acrylate by an Atom Transfer Radical Polymerization (ATRP) method, and the chemical modification of the polycaprolactone is expected to be realized. This process suffers from the following drawbacks in the polymerization process: (1) under the influence of macromolecular chains, the activity of carbon-bromine bonds (C-Br) at the ends of polycaprolactone chains is poor, and unsaturated monomers are difficult to effectively initiate to polymerize so as to realize modification; (2) because the fluorine-containing monomer block modified polycaprolactone is hydrophobic and has low polarity, the fluorine-containing monomer block modified polycaprolactone is difficult to dissolve in conventional organic solvents, and can be separated out from the conventional organic solvent system at the initial stage of block polymerization. Therefore, the fluorine-containing polymer block accessed during chemical modification is short, the modification effect is not ideal and the controllability is poor, and the Atom Transfer Radical Polymerization (ATRP) initiator is difficult to dissolve by using a solvent (such as an organic fluorine solvent) capable of dissolving the block-modified polycaprolactone.

In addition, the fluoropolymer is less susceptible to degradation than PCL. For example, since the carbon-fluorine bond (C-F) in the fluoroalkyl chain has a bond energy of 460kJ/mol, which is about 4 times that of the carbon-carbon bond (C-C), the carbon-fluorine bond is very stable and is difficult to cleave, and as such, the fluorine-containing compound is difficult to decompose and has accumulative properties and biotoxicity. This chemical structure makes it difficult for the fluoropolymer to degrade in the form of pendant groups. In addition, the fluorine-containing material can impart excellent liquid repellency and low surface energy and low polarity to the polymer, thereby being unfavorable for degradation by bioadsorption. Because of these properties of fluoropolymer, it is necessary to develop a fluoropolymer having degradation ability.

Disclosure of Invention

The invention aims to provide block modified polycaprolactone which is fluorine-containing alkyl polyacrylate block modified polycaprolactone.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

the hydrophobic polycaprolactone has the following chemical structural formula:

wherein Rf is a fluoroalkyl group; r is H or alkyl; m is 35 to 1300; n is 5 to 100; the asterisks are derived from the starting polycaprolactone.

Preferably, the fluoroalkyl group is nonafluoropentyl, tridecafluorooctyl, heptadecafluorodecyl, hexafluorobutyl, dodecafluoroheptyl or octafluoropentyl (-CH)₂(CF₂)₃CF₃、-CH₂(CF₂)₅CF₃、-CH₂(CF₂)₇CF₃、-CF₂CFHCF₃、-CH₂(CF₂)₄H、-(CF₂)₆H) One of (1); the alkyl group is a methyl group.

The invention also discloses a preparation method of the hydrophobic polycaprolactone, which comprises the following steps:

(1) reacting polycaprolactone with an amino alcohol compound to prepare hydroxyl-terminated polycaprolactone;

(2) reacting hydroxyl-terminated polycaprolactone with anhydride to prepare carboxyl-terminated polycaprolactone;

(3) reacting ethylene glycol bromoisobutyrate with fluorine-containing alkyl acrylate to prepare hydroxyl-terminated fluorine-containing polyacrylate;

(4) and reacting the carboxyl-terminated polycaprolactone with hydroxyl-terminated fluorine-containing polyacrylate to prepare the hydrophobic polycaprolactone.

The invention also discloses a preparation method of the hydrophobic polycaprolactone film, which comprises the following steps:

(4) reacting carboxyl-terminated polycaprolactone with hydroxyl-terminated fluorine-containing polyacrylate to prepare hydrophobic polycaprolactone;

(5) dissolving hydrophobic polycaprolactone in an organic solvent at room temperature to prepare a solution; and naturally drying the solution at room temperature to form a film, and preparing the hydrophobic polycaprolactone film.

The invention also discloses a preparation method of the hydroxyl-terminated fluorine-containing polyacrylate, which comprises the following steps: stirring ethylene glycol bromoisobutyrate, pentamethyldiethylenetriamine and cuprous bromide at the temperature of 30-40 ℃ for 1-24 hours under nitrogen; and then adding fluorine-containing alkyl acrylate to react for 1-24 h at 50-90 ℃ to prepare the hydroxyl-terminated fluorine-containing polyacrylate.

In the invention, the molecular weight of the polycaprolactone is 4.56-14.82 ten thousand; the amino alcohol compound is 6-amino-1-hexanol; the acid anhydride is succinic anhydride; the fluorine-containing alkyl acrylate is one of nonafluoropentyl acrylate, tridecafluorooctyl methacrylate, heptadecafluorodecyl acrylate, heptadecafluorodecyl methacrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, dodecafluoroheptyl acrylate or octafluoropentyl acrylate.

In the invention, the mass ratio of the polycaprolactone to the amino alcohol compound is 1: 0.2-2; the mass ratio of the hydroxyl-terminated polycaprolactone to the acid anhydride is (1-200) to (0.5-2); the mass ratio of the bromoisobutyric acid ethylene glycol ester to the fluorine-containing alkyl acrylate is (1 × 10)^-6～5×10^-5) 0.5 to 5; the mass ratio of the carboxyl-terminated polycaprolactone to the hydroxyl-terminated fluorine-containing polyacrylate is (1-4) to (0.05-10).

In the invention, the reaction in the step (1) is carried out for 1-24 hours at room temperature under the protection of nitrogen; the reaction in the step (2) is carried out at room temperature for 1-6 h under the protection of nitrogen; the reaction in the step (3) is carried out for 1-24 h at 50-90 ℃; the reaction in the step (4) is carried out for 1-8 h at 30-65 ℃.

In the present invention, the reaction of step (1) is carried out in an organic solvent; the reaction in the step (2) is carried out in an organic solvent in the presence of anhydrous potassium carbonate and 4-dimethylaminopyridine; the reaction in the step (3) is carried out in an organic solvent in the presence of pentamethyldiethylenetriamine and cuprous bromide; the reaction of step (4) is carried out in an organic solvent in the presence of N, N' -carbonyldiimidazole.

In the invention, in the step (3), ethylene glycol bromoisobutyrate, pentamethyl diethylenetriamine and cuprous bromide are stirred for 1-24 hours at 30-40 ℃ under nitrogen; and then adding fluorine-containing alkyl acrylate to react for 1-24 h at 50-90 ℃ to prepare the hydroxyl-terminated fluorine-containing polyacrylate.

In the invention, in the step (4), carboxyl-terminated polycaprolactone and N, N' -carbonyl diimidazole react for 1-24 hours at room temperature under nitrogen; and then adding a hydroxyl-terminated fluorine-containing polyacrylate solution, and reacting at 30-65 ℃ for 1-8 h to prepare the hydrophobic polycaprolactone.

The invention further discloses application of the hydrophobic polycaprolactone in preparation of hydrophobic materials or biodegradable materials; application of hydroxyl-terminated fluorine-containing polyacrylate in preparing hydrophobic polycaprolactone material.

In the present invention, the purification treatment after completion of the above reaction can be performed as follows:

and (2) after the reaction in the step (1) is finished, adding the reaction solution into 10-300 parts of absolute ethyl alcohol, and separating out a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 1-2 times (by 3 times), and vacuum-drying at 30-50 ℃ for 1-24 h to obtain the hydroxyl-terminated polycaprolactone PCL-OH.

And (3) after the reaction in the step (2) is finished, filtering, adding 0.3-1.0 part of acetic acid into the filtrate, adding the solution into 20-500 parts of deionized water, and separating out a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 2-10 times (x 3 times), and vacuum-drying at 30-50 ℃ for 1-24 h to obtain carboxyl-terminated polycaprolactone PCL-COOH.

And (3) after the reaction in the step (3) is finished, adding 1-20 parts of THF and 1-20 parts of fluorine-containing organic solvent, and passing through a neutral alumina (200-mesh and 300-mesh) column to obtain a light yellow clear solution. And (3) carrying out reduced pressure rotary evaporation on the solution at the temperature of 30-70 ℃ to remove the solvent, then adding the crude product into 5-30 parts of anhydrous methanol, separating out a solid, filtering, washing 1-3 parts of the solid by 3 times by using n-hexane, and carrying out vacuum drying at the temperature of 30-100 ℃ for 1-24 hours to obtain the hydroxyl-terminated fluorine-containing polyacrylate.

After the reaction in the step (4) is finished, pouring the reaction liquid into 5-200 parts of n-hexane, separating out a crude product, filtering, washing with absolute ethyl alcohol for 2-10 times and 3 times, and drying in vacuum at 30-50 ℃ for 1-24 hours to obtain the fluoroalkyl polymer block modified polycaprolactone which is hydrophobic polycaprolactone.

The fluorine-containing organic solvent is one or two of trifluoromethyl benzene and 1, 3-bis (trifluoromethyl) benzene which are mixed in any proportion.

Firstly, end hydroxylation and carboxylation are carried out on high molecular weight polycaprolactone; then synthesizing hydroxyl-terminated fluorine-containing polyacrylate with controllable polymerization degree by an ATRP method; and finally, carrying out esterification reaction on carboxyl-terminated polycaprolactone and the pre-synthesized hydroxyl-terminated fluorine-containing polyacrylate under the activation of N, N' -Carbonyl Diimidazole (CDI) under mild conditions to obtain the fluorine-containing alkyl polyacrylate block modified polycaprolactone, wherein the reaction structural formula is shown in figure 1.

Compared with the prior art, the technical scheme provided by the invention has the beneficial effects that:

(1) after the high molecular weight PCL is activated by terminal carboxyl and N, N' -Carbonyl Diimidazole (CDI), the PCL can be directly condensed with an organic fluorine polymer containing active hydroxyl, the reaction degree is high, and the reaction condition is mild.

(2) The ATRP is used for preparing the end group activated fluorine-containing polymer in advance, and then the end group activated fluorine-containing polymer is connected into a PCL molecular chain, and because the fluorine-containing polymerization product is obtained in a homogeneous system, the polymerization degrees of the fluorine-containing polymerization product and the modified PCL are easy to control, and the molecular weight distribution of the obtained product is narrow. Meanwhile, the problem that the fluorine-containing polymer chain is difficult to directly generate at the end of the PCL chain in situ due to the change of solubility is solved.

(3) Degradable fluorine-containing high molecular material is obtained by introducing degradable segment Polycaprolactone (PCL) into a fluorine-containing polymer molecular structure; the molecular weight of the accessed PCL is controlled to obtain a block polymer, and fluorine-containing high polymer materials with different degradation properties can be obtained; the PCL block modified fluoropolymer is prepared by directly condensing carboxyl-terminated PCL with an organic fluoropolymer containing active hydroxyl under the action of an activating agent under mild reaction conditions, so that the PCL can be prevented from thermal degradation in the whole preparation reaction process.

(4) The block modified PCL prepared according to the invention can avoid degradation of PCL, so that the obtained hydrophobic Polycaprolactone (PCL) product has high molecular weight, simple and convenient preparation process, easily obtained raw materials, and easy industrial production, popularization and application.

Drawings

FIG. 1 is a schematic diagram of the reaction for preparing the hydrophobic polycaprolactone of the present invention;

FIG. 2 is a schematic structural diagram of the hydrophobic polycaprolactone of example 1;

FIG. 3 is a schematic structural diagram of the hydrophobic polycaprolactone of example 2;

FIG. 4 is a schematic structural diagram of the hydrophobic polycaprolactone of example 3;

FIG. 5 is a schematic structural diagram of the hydrophobic polycaprolactone of example 4;

FIG. 6 is a schematic structural diagram of the hydrophobic polycaprolactone of example 5;

FIG. 7 is a schematic structural diagram of the hydrophobic polycaprolactone of example 6;

FIG. 8 is a schematic structural view of the hydrophobic polycaprolactone of example 7;

FIG. 9 is a schematic structural diagram of the hydrophobic polycaprolactone of example 8;

FIG. 10 is a schematic structural diagram of the hydrophobic polycaprolactone of example 9;

FIG. 11 is a schematic structural view of the hydrophobic polycaprolactone of example 10;

FIG. 12 is a schematic structural diagram of a hydrophobic polycaprolactone of comparative example 1;

fig. 13 is a water contact angle test chart of the unmodified Polycaprolactone (PCL) and the hydrophobic polycaprolactone film prepared by the embodiment of the invention. Wherein, PCL-PTFOA (2h) is the hydrophobic polycaprolactone film prepared in example 1, PCL-PTFOA (4h) is the hydrophobic polycaprolactone film prepared in example 2, PCL-PTFOA (6h) is the hydrophobic polycaprolactone film prepared in example 3, and PCL-PTFOA (8h) is the hydrophobic polycaprolactone film prepared in example 4;

FIG. 14 is an infrared absorption curve of unmodified Polycaprolactone (PCL) and hydrophobic polycaprolactone prepared according to the examples of the invention. Wherein, the curve a is unmodified polycaprolactone, the curve b is hydrophobic polycaprolactone prepared in the embodiment 1, the curve c is hydrophobic polycaprolactone prepared in the embodiment 2, the curve d is hydrophobic polycaprolactone prepared in the embodiment 3, and the curve e is hydrophobic polycaprolactone prepared in the embodiment 4;

FIG. 15 is a NMR chart of unmodified Polycaprolactone (PCL) and hydrophobic polycaprolactone prepared according to the examples of the invention. Wherein, the curve (1) is unmodified polycaprolactone, the curve (2) is hydrophobic polycaprolactone prepared in the embodiment 1, the curve (3) is hydrophobic polycaprolactone prepared in the embodiment 2, the curve (4) is hydrophobic polycaprolactone prepared in the embodiment 3, and the curve (5) is hydrophobic polycaprolactone prepared in the embodiment 4;

FIG. 16 is a photograph showing the degradation process of a polycaprolactone-modified fluoropolymer of the invention;

FIG. 17 is an SEM topography of the degradation process of the hydrophobic polycaprolactone of the invention;

FIG. 18 is a photograph of a polycaprolactone solution containing fluorine in accordance with the present invention, wherein (a) the solvent is dichloromethane and the concentration of the solution is 2 wt%; (b) the solvent is tetrahydrofuran, and the concentration of the solution is 3 wt%; (c) the solvent is dichloromethane, and the concentration of the solution is 10 wt%;

FIG. 19 is a photograph of a fluorinated polycaprolactone film of the invention, wherein (a) the solvent is dichloromethane and the concentration of the solution is 3 wt%; (b) the solvent was tetrahydrofuran, and the solution concentration was 10 wt%.

Detailed Description

The invention is further described below with reference to the figures and examples.

Example 1

(1) Polycaprolactone end hydroxylation

50.0g of PCL with a molecular weight of 8 ten thousand was dissolved in 500g of 1, 4-dioxane at 37 ℃, and 51g of 6-amino-1-hexanol was added under nitrogen protection to react for 8 hours. After the reaction, the reaction solution was slowly added to 1000g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 100g × 3 times, vacuum drying at 37 ℃ for 24h gave 39.6g of product, 79.2% yield. The product molecular weight was measured to be 69800.

(2) Polycaprolactone end carboxylation

25.0g of the prepared hydroxyl-terminated polycaprolactone (PCL-OH) and 28.5g of succinic anhydride are added into 500g of 1, 4-dioxane. After stirring to dissolve, 9.85g of anhydrous potassium carbonate (K) was added₂CO₃) And 8.70g of 4-Dimethylaminopyridine (DMAP) under nitrogen atmosphere at room temperature for 2 h. After the reaction was completed, filtration was performed, 15g of acetic acid was added to the filtrate, and the solution was added to 1000g of deionized water to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 120g × 3 times, vacuum drying at 37 ℃ for 24h gave 21.5g of product with a yield of 86.0%. The product molecular weight was found to be 68500.

(3) Preparation of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) by ATRP method

Dissolving 420ug of ethylene glycol bromoisobutyrate and 642ug of Pentamethyldiethylenetriamine (PMDETA) in 60g of 2-butanone, adding 0.4g of cuprous bromide, and stirring and reacting at 40 ℃ for 15min under the protection of nitrogen to obtain the catalyst. 63.0g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) was added thereto, heated to 80 ℃ and reacted for 2 hours. After the reaction was completed, 300g of THF and 100g of trifluorotoluene were added, and the mixture was passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solution was subjected to rotary evaporation of the solvent under reduced pressure at 65 ℃ and then the crude product was added to 950g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times and vacuum-dried at 55 ℃ for 24 hours to obtain 57.1g of hydroxyl-terminated fluorine-containing polyacrylate in a yield of 90.6%.

(4) Preparation of Block polymers by esterification

7.0g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 80g of anhydrous THF at room temperature in a three-necked flask, 4.7g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 0.5g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 30g of trifluorotoluene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 3 hours at the temperature of 53-55 ℃. After the reaction is finished, the reaction solution is poured into 280g of n-hexane, a crude product is separated out, the crude product is filtered, washed by absolute ethyl alcohol for 45g multiplied by 3 times, and dried in vacuum at 37 ℃ for 3h, so that 6.5g of hydrophobic polycaprolactone, namely the fluorinated alkyl polymer block modified polycaprolactone is obtained, and the yield is 86.7%. The product molecular weight was measured to be 72800. The structural formula of the product is shown in figure 2.

(5) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of dichloromethane to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Water was selected as the test drop with a volume of 3 μ L, and the average contact angle was 108.0 ± 0.8 ° (the contact angle of unmodified polycaprolactone to water was 96.8 ± 1.0 °) from five tests, see fig. 13.

Example 2

(1) Polycaprolactone end hydroxylation

50.0g of PCL with a molecular weight of 8 ten thousand was dissolved in 520g of 1, 4-dioxane at 37 ℃, and 49g of 6-amino-1-hexanol was added under nitrogen protection to react for 12 hours. After the reaction, the reaction solution was slowly added to 1050g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 100g × 3 times, vacuum drying at 37 ℃ for 24h gave 37.9g of product in 75.8% yield. The product molecular weight was determined to be 67500.

(2) Polycaprolactone end carboxylation

25.0g of the prepared hydroxyl-terminated polycaprolactone (PCL-OH) and 29.2g of succinic anhydride are added into 510g of 1, 4-dioxane. After stirring to dissolve, 9.88g of anhydrous potassium carbonate (K) was added₂CO₃) And 8.75g of 4-Dimethylaminopyridine (DMAP) under nitrogen atmosphere at room temperature for 4 h. After the reaction, the mixture was filtered, and 15g of acetic acid was added to the filtrate, and the solution was added to 990g of deionized water to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 120g × 3 times, vacuum drying at 37 ℃ for 24h gave 21.1g of product with a yield of 84.4%. The product molecular weight was found to be 67700.

423ug of ethylene glycol bromoisobutyrate and 645ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 65g of 2-butanone, 0.4g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 63.5g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) were added and the mixture was heated to 78 ℃ and reacted for 4 hours. After the reaction was completed, 310g of THF and 105g of m- (bistrifluoromethyl) benzene were added and passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solution was subjected to rotary evaporation under reduced pressure at 65 ℃ to remove the solvent, and then the crude product was added to 960g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times, and vacuum-dried at 55 ℃ for 24 hours to obtain 56.2g of hydroxyl-terminated fluorine-containing polyacrylate with a yield of 88.5%.

(4) Preparation of Block polymers by esterification

7.1g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 85g of anhydrous THF at room temperature in a three-necked flask, 4.8g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 0.5g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 32g of m- (bis (trifluoromethyl)) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction is finished, the reaction solution is poured into 310g of n-hexane, a crude product is separated out, the crude product is filtered, washed by absolute ethyl alcohol for 45g multiplied by 3 times, and dried in vacuum at 37 ℃ for 3h, so that 6.8g of the fluorine-containing alkyl polymer block modified polycaprolactone is obtained, and the yield is 89.5%. The molecular weight of the product was determined to be 77000. The structural formula of the product is shown in figure 3.

(5) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of Tetrahydrofuran (THF) to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Selecting water as test drop with volume of 3 μ L, and testing five times to obtain average contact angle of 116.0 + -1.2 deg., see FIG. 13; after undergoing 72 hours of enzymatic degradation, 87.9% was degraded.

Example 3

(1) The procedures of polycaprolactone end hydroxylation and polycaprolactone end carboxylation are the same as in example 1.

(2) Preparation of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) by ATRP method

418ug of ethylene glycol bromoisobutyrate and 620ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 60g of 2-butanone, 0.6g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 65.6g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) were added, heated to 80 ℃ and reacted for 6 hours. After the reaction was completed, 360g of THF and 120g of benzotrifluoride were added and the mixture was passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solution was subjected to rotary evaporation under reduced pressure at 65 ℃ to remove the solvent, and the crude product was added to 1050g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times, and vacuum-dried at 55 ℃ for 24 hours to obtain 55.3g of hydroxyl-terminated fluorine-containing polyacrylate in 84.3% yield.

(3) Preparation of Block polymers by esterification

7.0g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 100g of anhydrous THF at room temperature in a three-necked flask, and 5.1g N, N' -Carbonyldiimidazole (CDI) was added and reacted at 30 ℃ for 2 hours under nitrogen protection. 0.7g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 40g of trifluorotoluene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 4 hours at the temperature of 51-55 ℃. After the reaction is finished, the reaction solution is poured into 350g of n-hexane, a crude product is separated out, the crude product is filtered, washed by absolute ethyl alcohol for 45g multiplied by 3 times, and dried in vacuum at 37 ℃ for 3h, so that 7.1g of the fluorine-containing alkyl polymer block modified polycaprolactone is obtained, and the yield is 92.2%. The product molecular weight was measured to be 78700. The structural formula of the product is shown in figure 4.

(4) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of tetrahydrofuran to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Water was selected as the test drop with a drop volume of 3 μ L and five tests gave an average contact angle of 128.4 ± 1.3 °, see fig. 13.

Example 4

(1) The steps of polycaprolactone end hydroxylation and polycaprolactone end carboxylation are the same as in example 2.

490ug of ethylene glycol bromoisobutyrate and 655ug of Pentamethyldiethylenetriamine (PMDETA) were dissolved in 60g of 2-butanone, and after dissolution, 0.5g of cuprous bromide was added, and the mixture was stirred and reacted at 40 ℃ for 15min under the protection of nitrogen, to obtain a catalyst. 66.1g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) was added, heated to 80 ℃ and reacted for 8 hours. After the reaction was completed, 380g of THF and 155g of bis (trifluoromethyl) benzene were added and passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solution was subjected to rotary evaporation of the solvent under reduced pressure at 65 ℃ and the crude product was added to 1050g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times and dried under vacuum at 55 ℃ for 24 hours to obtain 57.3g of hydroxyl-terminated fluorine-containing polyacrylate in 86.7% yield.

(3) Preparation of Block polymers by esterification

7.2g of carboxyl-terminated polycaprolactone (PCL-COOH) were dissolved in 80g of anhydrous THF at room temperature in a three-necked flask, 4.9g N, N' -Carbonyldiimidazole (CDI) were added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 0.55g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 30g of bis (trifluoromethyl) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 4 hours at the temperature of 50-54 ℃. After the reaction is finished, the reaction solution is poured into 310g of n-hexane, a crude product is separated out, the crude product is filtered, washed by absolute ethyl alcohol for 45g multiplied by 3 times, and dried in vacuum at 37 ℃ for 3h, so that 6.3g of the fluorine-containing alkyl polymer block modified polycaprolactone is obtained, and the yield is 81.3%. The product molecular weight was measured to be 79900. The structural formula of the product is shown in figure 5.

(4) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of dichloromethane to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Water was selected as the test drop with a drop volume of 3 μ L and five tests gave an average contact angle of 127.3 ± 0.8 °, see fig. 13.

Example 5

(1) Polycaprolactone end hydroxylation

125.0g of PCL with the molecular weight of 5 ten thousand is dissolved in 850g of 1, 4-dioxane at 37 ℃, 25g of 6-amino-1-hexanol is added under the protection of nitrogen, and the reaction is carried out for 12 hours. After the reaction, the reaction mixture was slowly added to 650g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 60g × 3 times, vacuum drying at 37 ℃ for 24h gave 87.8g of product in 70.2% yield. The molecular weight of the product was determined to be 50500.

(2) Polycaprolactone end carboxylation

62.5g of the prepared hydroxyl-terminated polycaprolactone (PCL-OH) and 29.5g of succinic anhydride are added into 620g of 1, 4-dioxane. After stirring to dissolve, 9.98g of anhydrous potassium carbonate (K) was added₂CO₃) And 8.97g of 4-Dimethylaminopyridine (DMAP) were reacted at room temperature for 4 hours under a nitrogen atmosphere. After the reaction, the mixture was filtered, 15g of acetic acid was added to the filtrate, and the solution was added to 1020g of deionized water to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 120g × 3 times, vacuum drying at 37 ℃ for 24h gave 48.8g of product in 78.0% yield. The molecular weight of the product was determined to be 49800.

(3) Preparation of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) by ATRP method

453ug of bromoisobutyric acid ethylene glycol ester and 662ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 65g of 2-butanone, 0.6g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 67.1g of 1H,1H, 3H-hexafluorobutyl methacrylate (HFBMA) was added thereto, and the mixture was heated to 80 ℃ to react for 12 hours. After the reaction was completed, 350g of THF and 115g of trifluoromethylbenzene were added and the mixture was passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solvent was rotary-distilled off under reduced pressure at 55 ℃ to remove the solvent, and then the crude product was added to 1020g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times, and vacuum-dried at 55 ℃ for 24 hours to give 61.8g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) in a yield of 92.1%.

(4) Preparation of Block polymers by esterification

45.1g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 255g of anhydrous THF at room temperature in a three-necked flask, and 5.1g N, N' -Carbonyldiimidazole (CDI) was added and reacted at 30 ℃ for 2 hours under nitrogen protection. 0.6g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) is dissolved in 32g of trifluoromethylbenzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at 50-55 ℃. After the reaction, the reaction solution was poured into 330g of n-hexane to precipitate a crude product, which was then filtered, washed with absolute ethanol 45g × 3 times, and vacuum-dried at 37 ℃ for 3 hours to obtain 42.0g of fluoroalkyl polymer block-modified polycaprolactone with a yield of 92.0%. The product molecular weight was measured to be 59100. The structural formula of the product is shown in figure 6.

(5) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of Tetrahydrofuran (THF) to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Water was selected as the test drop, the drop volume was 3 μ L, and the average contact angle was 109.0 ± 1.0 ° when tested five times.

Example 6

(1) The polycaprolactone end hydroxylation and polycaprolactone end carboxylation were as in example 5.

(2) Preparation of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) by ATRP method

Dissolving 450ug of ethylene glycol bromoisobutyrate and 666ug of Pentamethyldiethylenetriamine (PMDETA) in 65g of 2-butanone, adding 0.5g of cuprous bromide, and stirring and reacting at 40 ℃ for 15min under the protection of nitrogen to obtain the catalyst. 66.8g of 1H,1H, 3H-hexafluorobutyl methacrylate (HFBMA) was added thereto, and the mixture was heated to 80 ℃ to react for 5 hours. After the reaction was completed, 345g of THF and 110g of trifluoromethylbenzene were added and the mixture was passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solvent was removed by rotary evaporation under reduced pressure at 55 ℃ and the crude product was added to 1010g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 150g X3 times and dried under vacuum at 55 ℃ for 24 hours to give 58.1g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) in a yield of 87.0%.

(3) Preparation of Block polymers by esterification

45.3g of carboxyl-terminated polycaprolactone (PCL-COOH) were dissolved in 285g of anhydrous THF at room temperature in a three-necked flask, and 5.2g N, N' -Carbonyldiimidazole (CDI) was added and reacted at 30 ℃ for 2 hours under nitrogen protection. 0.4g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) is dissolved in 31g of trifluoromethyl benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 52-55 ℃. After the reaction is finished, the reaction solution is poured into 320g of n-hexane, a crude product is separated out, the crude product is filtered, washed by absolute ethyl alcohol for 45g multiplied by 3 times, and dried in vacuum at 37 ℃ for 3h, so that 41.4g of the fluorine-containing alkyl polymer block modified polycaprolactone is obtained, and the yield is 90.5%. The product molecular weight was determined to be 49120. The structural formula of the product is shown in figure 7.

(4) Hydrophobicity test

At room temperature, 0.5g of the fluoroalkyl polymer block-modified polycaprolactone was dissolved in 10g of Tetrahydrofuran (THF) to prepare a solution with a mass concentration of 5%. The solution is poured into a watch glass and naturally dried to form a film at room temperature. The contact angle of the polymer film was measured by using a full-automatic micro-droplet wettability measuring instrument model OCAH 200 from dataphysics, usa, to evaluate the surface wettability of the polymer. Selecting water as a test liquid drop, wherein the volume of the liquid drop is 3 mu L, and the average contact angle is 106.0 +/-0.8 degrees after five times of tests; after undergoing 72 hours of enzymatic degradation, 86.2% was degraded.

Example 7

(1) Preparation of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) by ATRP method

210ug of ethylene glycol bromoisobutyrate and 320ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 30g of 1, 3-bis (trifluoromethyl) benzene, 0.2g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 32.5g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) were added, heated to 80 ℃ and reacted for 24 hours. After the reaction was completed, 250g of 1,3- (bistrifluoromethyl) benzene was added and passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solvent was removed by rotary evaporation under reduced pressure at 75 ℃ from the solution, and then the crude product was added to 510g of anhydrous methanol to precipitate a solid, which was then filtered, washed with n-hexane 60g X3 times, and vacuum-dried at 55 ℃ for 24 hours to obtain 29.6g of hydroxyl-terminated fluorine-containing polyacrylate, whose number-average molecular weight was 6030 and yield was 91.2%.

(2) Polycaprolactone end carboxylation

125.0g of PCL with a molecular weight of 4500 are dissolved in 850g of 1, 4-dioxane at 37 ℃, and 25g of 6-amino-1-hexanol is added under the protection of nitrogen to react for 12 h. After the reaction, the reaction mixture was slowly added to 650g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 60g multiplied by 3 times, and vacuum drying at 37 ℃ for 24h to obtain the product, namely the hydroxyl-terminated polycaprolactone with the yield of 76.2%. The molecular weight of the product was 4000.

25.0g (PCL-OH) of hydroxyl-terminated Polycaprolactone (PCL) with a molecular weight of 4000 and 0.7g of succinic anhydride were added to 110g of 1, 4-dioxane. After stirring to dissolve, 1.9g of anhydrous potassium carbonate (K) was added₂CO₃) And 2.5g of 4-Dimethylaminopyridine (DMAP) under nitrogen atmosphere at room temperature for 4 h. After the reaction was completed, filtration was performed, 4g of acetic acid was added to the filtrate, and the solution was added to 300g of deionized water to precipitate a solid. Filtration, washing of the filter cake with anhydrous ethanol 250g × 3 times, vacuum drying at 37 ℃ for 24h gave 18.5g, 74.1% yield of product. The product was found to have a molecular weight of 4520.

(3) Preparation of Block polymers by esterification

4.2g of carboxyl-terminated polycaprolactone (PCL-COOH) were dissolved in 45g of anhydrous THF at room temperature in a three-necked flask, 0.3g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 5.9g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 65g of 1,3- (bis (trifluoromethyl)) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction, the reaction solution was poured into 350g of n-hexane to precipitate a crude product, which was then filtered, washed with absolute ethanol 50g × 3 times, and vacuum-dried at 37 ℃ for 3 hours to obtain 7.1g of polycaprolactone block-modified fluoroalkyl polymer (PCL 4000-PTFOA) with a yield of 70.3%. The molecular weight of the product was found to be 10080. The structural formula of the product is shown in figure 8.

(4) Degradability test

2g of a polycaprolactone block-modified fluoroalkyl polymer (PCL 4000-PTFOA) was dissolved in 20mL of tetrahydrofuran, and then transferred to a petri dish, placed horizontally in an oven, and dried at 40 ℃ for 24 hours. The film was cut into circular sheets of about 10mm in diameter, weighing about 0.04 g. And (3) cleaning the cut wafer in ethanol to remove impurities on the surface of the film, finally cleaning the thin wafer by using deionized water, placing the wafer in a vacuum oven, and drying the wafer for 24 hours at 37 ℃ to obtain a clean thin wafer for degradation.

The prepared slices were reweighed separately and placed into the numbered plate wells, and 3mL of an 8U/mL (0.027 mg/mL) solution of aspergillus oryzae lipase in PBS (pH = 7.2-7.4) was pipetted into the corresponding plate wells. Each disc was completely immersed in the enzyme solution and three samples were set at each degradation time point to reduce occasional errors. After the materials are degraded for 12 hours, 24 hours, 48 hours and 72 hours respectively, the materials are taken out and washed by a large amount of deionized water, and soluble impurities on the surface are removed. Subsequently, the mixture was placed in a vacuum oven, dried at 37 ℃ for 24 hours, and weighed and recorded.

The weight loss ratio calculation formula is as follows, and the following examples and comparative examples also use this formula:

weight loss ratio (%) = (W)₀-W_i）/（W₀）

Wherein W₀Mass before degradation of the flakes, W_iIs the average mass of three samples after degradation.

The weight loss rates of the PCL4000-PTFOA samples at 12 hours, 24 hours, 48 hours and 72 hours were measured to be 2.1%, 22.3%, 43.5% and 77.2%, respectively. After the polycaprolactone block modified fluoroalkyl polymer product is subjected to enzyme catalytic degradation for 72 hours, 77.2% of degradation is carried out, and the average contact angle is tested five times to be 119.0 +/-1.1 degrees.

Example 8

(1) Preparation of hydroxy-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) by ATRP method example 2 is given.

(2) Polycaprolactone end carboxylation

125.0g of PCL with a molecular weight of 7000 is dissolved in 850g of 1, 4-dioxane at 37 ℃, 25g of 6-amino-1-hexanol is added under the protection of nitrogen, and the reaction is carried out for 12 h. After the reaction, the reaction mixture was slowly added to 650g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 60g multiplied by 3 times, and vacuum drying at 37 ℃ for 24h to obtain the product, namely the hydroxyl-terminated polycaprolactone with the yield of 73.2%. The product was measured to have a molecular weight of 6100.

38.0g (PCL-OH) of hydroxyl-terminated Polycaprolactone (PCL) with molecular weight of 6000 and 0.8g of succinic anhydride are added into 150g of 1, 4-dioxane. After stirring to dissolve, 1.8g of anhydrous potassium carbonate (K) was added₂CO₃) And 2.6g of 4-Dimethylaminopyridine (DMAP) under nitrogen atmosphere at room temperature for 4 h. After the reaction was completed, filtration was performed, 5g of acetic acid was added to the filtrate, and the solution was added to 300g of deionized water to precipitate a solid. Filtration, washing of the filter cake with anhydrous ethanol 250g × 3 times, vacuum drying at 37 ℃ for 12h gave 30.4g of product, 80.2% yield. The product molecular weight was determined to be 6700.

(3) Preparation of Block polymers by esterification

6.5g of carboxyl-terminated polycaprolactone (PCL-COOH) were dissolved in 55g of anhydrous THF at room temperature in a three-necked flask, 0.4g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 5.9g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 65g of 1,3- (bis (trifluoromethyl)) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction, the reaction solution was poured into 350g of n-hexane to precipitate a crude product, which was then filtered, washed with absolute ethanol 50g × 3 times, and vacuum-dried at 37 ℃ for 10 hours to obtain 9.1g of polycaprolactone block-modified fluoroalkyl polymer (PCL 6000-PTFOA) with a yield of 73.4%. The product molecular weight was determined 12110. The structural formula of the product is shown in figure 9.

(4) Degradability test

2g of polycaprolactone block-modified fluoroalkyl polymer (PCL 6000-PTFOA) was dissolved in 20mL of tetrahydrofuran, and then transferred to a petri dish, horizontally placed in an oven, and dried at 40 ℃ for 24 hours. The film was cut into circular sheets of about 10mm in diameter, weighing about 0.04 g. And (3) cleaning the cut wafer in ethanol to remove impurities on the surface of the film, finally cleaning the thin wafer by using deionized water, placing the wafer in a vacuum oven, and drying the wafer for 24 hours at 37 ℃ to obtain a clean thin wafer for degradation.

The weight loss rates of the PCL6000-PTFOA samples at 12 hours, 24 hours, 48 hours and 72 hours were measured to be 1.9%, 21.8%, 43.8% and 80.2%, respectively. After the polycaprolactone block modified fluoroalkyl polymer product is subjected to enzyme catalysis degradation for 72 hours, 80.2% of the product is degraded, and the average contact angle is 123.2 +/-1.2 degrees after five times of tests.

Example 9

220ug of ethylene glycol bromoisobutyrate and 300ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 35g of 1, 3-bis (trifluoromethyl) benzene, 0.2g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 33.1g of 1H,1H,2H, 2H-tridecafluorooctyl acrylate (TFOA) was added, heated to 80 ℃ and reacted for 28 hours. After the reaction was completed, 265g of 1,3- (bistrifluoromethyl) benzene was added and passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solvent was removed by rotary evaporation under reduced pressure at 78 ℃ and the crude product was then added to 500g of anhydrous methanol to precipitate a solid, which was filtered, washed with n-hexane 60g X3 times and dried under vacuum at 65 ℃ for 24 hours to give 22.1g of hydroxyl-terminated fluorine-containing polyacrylate, which was found to have a number average molecular weight of 6630 and a yield of 66.7%.

(2) Polycaprolactone end carboxylation

125.0g of PCL with the molecular weight of 9800 is dissolved in 850g of 1, 4-dioxane at 37 ℃, 25g of 6-amino-1-hexanol is added under the protection of nitrogen, and the reaction is carried out for 12 hours. After the reaction, the reaction mixture was slowly added to 650g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 60g multiplied by 3 times, and vacuum drying at 37 ℃ for 24h to obtain the product, namely the hydroxyl-terminated polycaprolactone with the yield of 72.2%. The product molecular weight was determined to be 8210.

49.0g (PCL-OH) of hydroxyl-terminated Polycaprolactone (PCL) with a molecular weight of 8000 and 0.8g of succinic anhydride were added to 175g of 1, 4-dioxane. After stirring to dissolve, 1.9g of anhydrous potassium carbonate (K) was added₂CO₃) And 2.5g of 4-Dimethylaminopyridine (DMAP) under nitrogen atmosphere at room temperature for 4 h. After the reaction, the mixture was filtered, and 6g of acetic acid was added to the filtrate, and the solution was added to 300g of deionized water to precipitate a solid. Filtration, washing of the filter cake with anhydrous ethanol 250g × 3 times, vacuum drying at 37 ℃ for 24h gave 37.0g of product, 75.6% yield. The product molecular weight was determined to be 8020.

(3) Preparation of Block polymers by esterification

8.4g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 75g of 1,3- (bistrifluoromethyl) benzene in a three-necked flask at room temperature, 0.5g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 5.8g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 70g of 1,3- (bis (trifluoromethyl)) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction, the reaction solution was poured into 350g of n-hexane to precipitate a crude product, which was then filtered, washed with absolute ethanol 50g × 3 times, and vacuum-dried at 37 ℃ for 3 hours to obtain 9.2g of polycaprolactone block-modified fluoroalkyl polymer (PCL 8000-PTFOA) with a yield of 65.0%. The molecular weight of the product was determined to be 15090. The structural formula of the product is shown in figure 10.

(4) Degradability test

2g of a polycaprolactone block-modified fluoroalkyl polymer (PCL 8000-PTFOA) was dissolved in 20mL of tetrahydrofuran, and then transferred to a petri dish, placed horizontally in an oven, and dried at 40 ℃ for 24 hours. The film was cut into circular sheets of about 10mm in diameter, weighing about 0.04 g. And (3) cleaning the cut wafer in ethanol to remove impurities on the surface of the film, finally cleaning the thin wafer by using deionized water, placing the wafer in a vacuum oven, and drying the wafer for 24 hours at 37 ℃ to obtain a clean thin wafer for degradation.

The weight loss ratios of the PCL8000-PTFOA samples at 12 hours, 24 hours, 48 hours and 72 hours were measured to be 1.9%, 22.9%, 44.5% and 84.8%, respectively. After the polycaprolactone block modified fluoroalkyl polymer product underwent enzyme catalytic degradation for 72 hours, 84.8% of the product was degraded.

Example 10

(1) Preparation of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) by ATRP method

453ug of bromoisobutyric acid ethylene glycol ester and 662ug of Pentamethyldiethylenetriamine (PMDETA) are dissolved in 65g of 2-butanone, 0.6g of cuprous bromide is added after the dissolution, and the mixture is stirred and reacted for 15min at 40 ℃ under the protection of nitrogen, so that the catalyst is obtained. 67.1g of 1H,1H, 3H-hexafluorobutyl methacrylate (HFBDA) was added, heated to 80 ℃ and reacted for 28 hours. After the reaction was completed, 350g of THF and 115g of benzotrifluoride were added and the mixture was passed through a neutral alumina (200-300 mesh) column to obtain a pale yellow clear solution. The solution was rotary evaporated under reduced pressure at 55 ℃ to remove the solvent, then the crude product was added to 1020g of anhydrous methanol to precipitate a solid, which was filtered, washed with n-hexane 150g × 3 times, and vacuum-dried at 55 ℃ for 24 hours to give 61.8g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) having a molecular weight of 3950 and a yield of 92.1%.

(2) Polycaprolactone end carboxylation

329.0g (PCL-OH) of hydroxy-terminated polycaprolactone (PCL, prepared in example 5) having a molecular weight of 50500 and 0.8g of butyleneThe anhydride was added to 152g of 1, 4-dioxane. After stirring to dissolve, 1.9g of anhydrous potassium carbonate (K) was added₂CO₃) And 2.3g of 4-Dimethylaminopyridine (DMAP) under nitrogen at room temperature for 6 hours. After the reaction was completed, filtration was performed, 4g of acetic acid was added to the filtrate, and the solution was added to 300g of deionized water to precipitate a solid. Filtration, washing of the filter cake with anhydrous ethanol 250g × 3 times, vacuum drying at 37 ℃ for 24h gave 245.5g of product, 74.6% yield. The product molecular weight was determined to be 49900.

(3) Preparation of Block polymers by esterification

50.1g of carboxyl-terminated polycaprolactone with a molecular weight of 49900 was dissolved in 550g of 1,3- (bis-trifluoromethyl) benzene in a three-necked flask at room temperature, 0.5g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 5.8g of hydroxyl-terminated poly (1H, 1H, 3H-hexafluorobutyl methacrylate) is dissolved in 71g of trifluorotoluene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction, the reaction solution was poured into 860g of n-hexane to precipitate a crude product, which was then filtered, washed with anhydrous ethanol 200g × 3 times, and vacuum-dried at 37 ℃ for 3 hours to obtain 79.8g of polycaprolactone block-modified fluoroalkyl polymer (PCL 50000-PHFDA) with a yield of 80.1%. The molecular weight of the product was found to be 50230. The structural formula of the product is shown in figure 11.

(4) Degradability testing procedure as in example 7

The weight loss rates of the PCL50000-PHFDA sample at 12 hours, 24 hours, 48 hours and 72 hours were measured to be 2.2%, 23.4%, 41.2% and 86.3%, respectively. The polycaprolactone block modified fluoroalkyl polymer product was 86.3% degraded after 72 hours of enzymatic degradation.

Comparative example:

(1) preparation of hydroxy-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) by ATRP method as in example 7.

(2) Polycaprolactone end carboxylation

125.0g of PCL with the molecular weight of 2300 is dissolved in 850g of 1, 4-dioxane at 37 ℃, and 25g of 6-amino-1-hexanol is added under the protection of nitrogen to react for 12 h. After the reaction, the reaction mixture was slowly added to 650g of anhydrous ethanol with continuous stirring to precipitate a solid. Filtering, washing the filter cake with absolute ethyl alcohol for 60g multiplied by 3 times, and vacuum drying at 37 ℃ for 24h to obtain the product, namely the hydroxyl-terminated polycaprolactone with the yield of 75.6%. The molecular weight of the product was determined to be 2000.

12.4g (PCL-OH) of hydroxyl-terminated Polycaprolactone (PCL) with molecular weight of 2000 and 0.8g of succinic anhydride were added to 90g of 1, 4-dioxane. After stirring to dissolve, 1.6g of anhydrous potassium carbonate (K) was added₂CO₃) And 2.1g of 4-Dimethylaminopyridine (DMAP) under nitrogen at room temperature for 6 hours. After the reaction was completed, filtration was performed, 3g of acetic acid was added to the filtrate, and the solution was added to 200g of deionized water to precipitate a solid. Filtration, washing of the filter cake with absolute ethanol 150g × 3 times, vacuum drying at 37 ℃ for 24h gave 6.3g of product, 51.2% yield. The product molecular weight was found to be 1920.

(3) Preparation of Block polymers by esterification

2.0g of carboxyl-terminated polycaprolactone (PCL-COOH) was dissolved in 35g of anhydrous THF at room temperature in a three-necked flask, 0.3g N, N' -Carbonyldiimidazole (CDI) was added, and the mixture was reacted at 30 ℃ for 2 hours under nitrogen protection. 5.5g of hydroxyl-terminated poly (1H, 1H,2H, 2H-tridecafluorooctyl acrylate) is dissolved in 65g of 1,3- (bis (trifluoromethyl)) benzene to prepare a solution, the solution is added into a three-neck flask, and the reaction mixture reacts for 6 hours at the temperature of 50-55 ℃. After the reaction, the reaction solution was poured into 290g of n-hexane to precipitate a crude product, which was then filtered, washed with absolute ethanol 50g × 3 times, and vacuum-dried at 37 ℃ for 3 hours to obtain 6.8g of polycaprolactone block-modified fluoroalkyl polymer (PCL 2000-PTFOA), with a yield of 91.1%. The product was found to have a molecular weight of 8150. The structural formula of the product is shown in figure 12.

(4) Degradability test

2g of polycaprolactone block-modified fluoroalkyl polymer (PCL 2000-PTFOA) was dissolved in 20mL of tetrahydrofuran, and then transferred to a petri dish, placed horizontally in an oven, and dried at 40 ℃ for 24 h. The film was cut into circular sheets of about 10mm in diameter, weighing about 0.04 g. And (3) cleaning the cut wafer in ethanol to remove impurities on the surface of the film, finally cleaning the thin wafer by using deionized water, placing the wafer in a vacuum oven, and drying the wafer for 24 hours at 37 ℃ to obtain a clean thin wafer for degradation.

The weight loss rates of the PCL2000-PTFOA sample at 12 hours, 24 hours, 48 hours and 72 hours are respectively 1.5 percent, 5.2 percent, 8.0 percent and 12.1 percent, the product is degraded very slowly after the enzyme catalysis is carried out for 72 hours, and the average contact angle is 98.5 +/-1.3 degrees after five times of tests.

FIG. 14 is an infrared absorption curve of unmodified Polycaprolactone (PCL) and hydrophobic polycaprolactone prepared according to the examples of the invention. Wherein, curve a is unmodified polycaprolactone, curve b is the hydrophobic polycaprolactone prepared in example 1, curve c is the hydrophobic polycaprolactone prepared in example 2, curve d is the hydrophobic polycaprolactone prepared in example 3, and curve e is the hydrophobic polycaprolactone prepared in example 4. In FIG. 14, 2950.4 cm^-1And 2866.8 cm^-1The absorption peak at (A) is assigned to the symmetric and antisymmetric stretching vibration peak of-CH, 1728.0 cm^-1Absorption peak of expansion and contraction vibration at 1237.1 cm, which is attributed to C = O^-1、1190.1 cm^-1、1145.1 cm^-1、1082.3 cm^-1The peak at (A) is assigned to the characteristic absorption peak of C-F and is 1237.1 cm^-1、1190.1 cm^-1The peak overlaps with the characteristic absorption peak of C = O. Compared with the infrared absorption curve a of the unmodified PCL, the characteristic absorption peak of C-F appears in the infrared absorption curve of the modified PCL of the fluoropolymer block.

FIG. 15 is a NMR chart of unmodified Polycaprolactone (PCL) and hydrophobic polycaprolactone prepared according to the examples of the invention. Wherein, the curve (1) is unmodified polycaprolactone, and the curve (2) is the thinning prepared in the example 1A water-type polycaprolactone, wherein the curve (3) is the hydrophobic polycaprolactone prepared in example 2, the curve (4) is the hydrophobic polycaprolactone prepared in example 3, and the curve (5) is the hydrophobic polycaprolactone prepared in example 4. In FIG. 15, the peaks at 4.05 ppm, 2.31 ppm, 1.65 ppm and 1.39 ppm were assigned to-C in the structural unit of PCL chain, respectivelyH ₂-peak of (a). In curves (2), (3), (4), and (5), the peak at 4.31 ppm was assigned O = COCH ₂Peak of (2.42 ppm) is-CH₂C₆F₁₃Characteristic peak of (2).

FIG. 16 is a photograph showing the degradation process of a polycaprolactone-modified fluoropolymer of the invention; wherein, the PCL2000-PTFOA of the polycaprolactone 2000 (PCL 2000) block modified fluorine-containing polymer material of the comparative example is slowly degraded; the polycaprolactone block modified fluoropolymer materials PCL6000-PTFOA and PCL8000-PTFOA prepared in the embodiments 8 and 9 are mostly degraded after enzyme treatment for 72 hours, and the polycaprolactone 8000 (PCL 8000) block modified fluoropolymer material has less residue and is degraded more thoroughly.

FIG. 17 is an SEM topography of the degradation process of the hydrophobic polycaprolactone disclosed by the invention. Wherein 1, 2, 3 and 4 respectively represent a topography map before enzyme catalytic degradation, after 12h degradation, 48 h degradation and 72 h degradation; a is a topography of PCL4000-PTFOA prepared according to example 7 before enzymatic degradation, after degradation for 12h, 48 h and 72 h; b is a morphology chart of the PCL6000-PTFOA prepared according to the embodiment 8 before the enzyme catalytic degradation, after the degradation for 12h, 48 h and 72 h; c is a topography map of the PCL8000-PTFOA prepared in the example 9 before the enzyme catalytic degradation, after the degradation for 12h, 48 h and 72 h.

FIG. 18 is a photograph of a polycaprolactone solution containing fluorine in accordance with the present invention, wherein (a) the solvent is dichloromethane and the concentration of the solution is 2 wt%; (b) the solvent is tetrahydrofuran, and the concentration of the solution is 3 wt%; (c) the solvent is dichloromethane, and the concentration of the solution is 10 wt%; FIG. 19 is a photograph of a fluorinated polycaprolactone film of the invention, wherein (a) the solvent is dichloromethane and the concentration of the solution is 3 wt%; (b) the solvent was tetrahydrofuran, and the solution concentration was 10 wt%. The fluorine-containing polycaprolactone has good solubility and good film forming property.

The preparation method of the hydrophobic polycaprolactone utilizes an Atom Transfer Radical Polymerization (ATRP) method to synthesize hydrophobic fluoroalkyl polyacrylate, and then directly prepares a block polymer through high-molecular mutual condensation, and belongs to the field of high-molecular synthesis. According to the hydrophobic polycaprolactone and the preparation method thereof disclosed by the invention, as mild reaction conditions are adopted in the preparation process, the degradation of polycaprolactone is avoided, and the obtained modified PCL polymerization product has the advantages of controllable structure, high molecular weight, good film forming property and excellent processability. The fluorine-containing polyacrylate with controllable structure is introduced into the structure of the modified polycaprolactone, so that the hydrophobicity of the modified product can be controlled; due to the introduction of the polycaprolactone which can be biologically degraded and enzymatically degraded into the fluorine-containing polyacrylate structure, the modified product can be degraded.

Claims

1. The preparation method of the hydrophobic polycaprolactone is characterized by comprising the following steps:

the chemical structural formula of the hydrophobic polycaprolactone is as follows:

wherein Rf is a fluoroalkyl group; r is H or alkyl; m is 35 to 1300; n is 5 to 100;

the molecular weight of the polycaprolactone is 4.56-14.82 ten thousand; the amino alcohol compound is 6-amino-1-hexanol; the acid anhydride is succinic anhydride; the fluorine-containing alkyl acrylate is one of nonafluoropentyl acrylate, tridecafluorooctyl methacrylate, heptadecafluorodecyl acrylate, heptadecafluorodecyl methacrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, dodecafluoroheptyl acrylate or octafluoropentyl acrylate; the fluorine-containing alkyl is one of nonafluoropentyl, tridecafluorooctyl, heptadecafluorodecyl, hexafluorobutyl, dodecafluoroheptyl or octafluoropentyl; the alkyl group is a methyl group;

the mass ratio of the polycaprolactone to the amino alcohol compound is 1: 0.2-2; the mass ratio of the hydroxyl-terminated polycaprolactone to the acid anhydride is (1-200) to (0.5-2); the mass ratio of the bromoisobutyric acid ethylene glycol ester to the fluorine-containing alkyl acrylate is (1 × 10)^-6～5×10^-5) 0.5 to 5; the mass ratio of the carboxyl-terminated polycaprolactone to the hydroxyl-terminated fluorine-containing polyacrylate is (1-4) to (0.05-10);

the reaction in the step (1) is carried out for 1-24 hours at room temperature under the protection of nitrogen; the reaction in the step (2) is carried out at room temperature for 1-6 h under the protection of nitrogen; the reaction in the step (3) is carried out for 1-24 h at 50-90 ℃; the reaction in the step (4) is carried out for 1-8 h at 30-65 ℃;

the reaction of step (1) is carried out in an organic solvent; the reaction in the step (2) is carried out in an organic solvent in the presence of anhydrous potassium carbonate and 4-dimethylaminopyridine; the reaction in the step (3) is carried out in an organic solvent in the presence of pentamethyldiethylenetriamine and cuprous bromide; the reaction in the step (4) is carried out in an organic solvent in the presence of N, N' -carbonyldiimidazole;

in the step (4), the carboxyl-terminated polycaprolactone and N, N' -carbonyl diimidazole react for 1-24 hours at room temperature under nitrogen; and then adding a hydroxyl-terminated fluorine-containing polyacrylate solution, and reacting at 30-65 ℃ for 1-8 h to prepare the hydrophobic polycaprolactone.